芹菜黄酮合成酶Ⅰ基因的克隆与序列分析

Cloning and sequence analysis of flavone synthase I gene in Apium graveolens

选用3个芹菜材料六合黄心芹、津南实芹和美国西芹,分别从中克隆了合成黄酮类化合物的关键酶基因——芹菜黄酮合成酶I基因(AgFS I)。该基因全长均为1 616 bp,含有359 bp的内含子I和190 bp的内含子II。芹菜AgFS I基因编码355个氨基酸,属于20G-FeII_Oxy超级家族。序列分析结果显示,3种芹菜中AgFS I基因在核苷酸水平上有5个碱基的差异,编码的氨基酸有5个位点的差异。芹菜黄酮合成酶I(AgFS I)与其他来源植物的FSI氨基酸多重序列比对分析结果表明,该酶具有高度保守性。对AgFS I进行进化树分析,氨基酸序列的疏水性/亲水性分析,三级结构预测与分析,结果显示AgFS I与同属于伞形科的胡萝卜和孜然芹的FSI进化关系最近,AgFS I属于疏水性蛋白质,3种芹菜AgFS I的空间结构相似。

The flavone synthase I gene （AgFS I）, the key gene for flavonoids synthesis, was cloned from Apium graveolens cultivars Liuhehuangxinqin, Jinnanshiqin and Meiguoxiqin, respectively. The length of AgFS I gene was 1 616 bp, containing 359-bp intronⅠ and 190-bp intronⅡ. The AgFS I gene encodes 355 amino acids, belonging to the 20G-FeII Oxy superfamily. There were differences in 5 nucleotide sites and 5 amino acid sites among the three cultivars of Api-um graveolens. Multiple sequence alignment of AgFS Is with FSIs from other plants showed that FSⅠs were highly conser-vative. Phylogenetic tree revealed the AgFS Is had the closest relationship to Daucus carota and Cuminum cyminum, which belong to the Apiaceae. Amino acid sequence analyses indicate that AgFS I belong to the hydrophobic protein. The AgFS Is from three cultivars of Apium graveolens are similar in three dimentional structure.